Solar Thermal (Water) Heating

solar thermal panels

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What is solar water heating?

Solar water panels trap the sun’s heat in panels or tubes for use in homes, other buildings and swimming pools. They need a hot water tank to store the heated water. Because of this there are only a small number of combination (combi) boilers that can be used with this technology, and they can be more expensive. Here in Britain (yes, even here in Yorkshire!), solar water heating can provide 50 to 70% of the hot water for a home. Hot water bills are reduced by at least half and nearly all of the hot water required during the summer is provided. Solar systems usually give at least 20 to 30 years useful service, during which time the money saved more than repays the initial cost.

How does solar water heating work?

A typical system consists of a heat collector, usually mounted on a roof. It needs to face as near to south as possible (SE to SW is ideal). Water is forced through the collector where it is heated by the sun, then through a coil in the hot water cylinder to transfer its heat to the surrounding water, ready for use.

The solar panels are not obtrusive (it’s similar to having a Velux skylight on your roof) and can either sit on an existing roof or can be built into it. They can either be professionally installed or you can do the work yourself. Most modern systems are manufactured to ISO: 9002 quality standards, and come with a warranty of up to 10 years.

How hot does the water get?

On sunny days, temperatures of 70 to 85 degrees are common. Even on cloudy days in winter some hot water will be produced.

How many panels will I need?

A typical installation for a family of four would need about 4 square metres of panels (usually two standard panels).

Will I need planning permission?

Not usually, unless you live in a Listed Building or Conservation Area. Contact your local authority planning department for advice and also check if building regulations might apply. If there are problems installing the panels on the roof, it may be possible to put a system in the grounds of your house.

How much does it cost?

The cost of a professionally installed system can vary from £2,000 to £4,000 depending on the size and type of system. A DIY installation would reduce this cost to a minimum of £1,200.

Other sources of information on this technology

Alternative Technology Centre

The Energy Savings Trust

Solar Trade Association

Heat Pump Association

Yorkshire and Humber Microgeneration partnership

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